Flavoring with 2,4,4-trimethyl-3-(buta-1,3-dienyl)cyclohex-2-en-one

ABSTRACT

Flavorants comprising 2,4,4-trimethyl-3-(buta-1,3-dienyl)cyclohex-2-en-1-one.

This is a division of application Ser. No. 889,070 filed Mar. 22, 1978.

FIELD OF THE INVENTION

This invention relates to the field of odorants and flavorants.

SUMMARY OF THE INVENTION

The present invention relates to novel odorant and/or flavoringsubstances. More particularly, the invention is concerned with compoundsof the general formula ##STR1## , wherein R represents a butyl,but-2-en-yl or 1,3-butadienyl group, a process for the manufacturethereof and odorant and/or a flavoring compositions containing same. Theinvention is also concerned with a method of imparting an odor and/orflavor to materials using said compounds of formula I or saidcompositions.

DESCRIPTION OF PREFERRED EMBODIMENTS

Formula I hereinbefore is intended to collectively embrace compounds ofthe formula ##STR2##

The foregoing formula are intended to embrace all possible geometricisomers having regard to the cis/trans isomerism present.

According to the process provided by the present invention, thecompounds of formula I hereinbefore are manufactured by

(a) heating 4-(2,6,6-trimethyl-3-oxo-1-cyclohexen-1-yl)-but-3-en-2-ol inan acid medium and, if desired, hydrogenating the exocyclic double bondspresent in the reaction product obtained,

or

(b) subjecting 3-oxodihydro-β-ionyl acetate to pyrolysis.

The acid medium required for embodiment (a) of the process aforesaid canbe produced with the aid of mineral acids such as sulphuric acid orhydrochloric acid, acid salts such as bisulphates (e.g. potassiumbisulphate) or acidic earths such as diatomaceous earth (e.g. Filtrol).However, suitable organic acids such as those organic acids which aremoderately strong to strong can also be used. Examples of such organicacids are alkanesulphonic acids (e.g. methanesulphonic acid) and picricacid.

The reaction temperature is not critical. It conveniently lies in therange of ca 20°-200° C., preferably 60°-130° C. The temperature isconveniently higher when a weaker acid is used and lower when a strongeracid is used.

The reaction is preferably carried out in the presence of an organicsolvent, especially an aromatic solvent such as benzene, toluene, xyleneetc.

The hydrogenation of the exocyclic double bonds present in a compound offormula Ia is carried out according to methods known per se,conveniently catalytically. Suitable catalysts are noble metals (e.g.palladium, platinum and rhenium) or nickel (e.g. Raney-nickel) etc. Thehydrogenation is preferably carried out in the presence of a solventsuch as water, ethanol, methanol, dioxan etc.

The hydrogenation is conveniently carried out at room temperature,although it can also be carried out at a lower or higher temperature(e.g. 5° C. to 100° C.) depending on the catalyst and solvent used.

The pyrolysis of the known 3-oxo-dihydro-β-ionyl acetate [see, forexample, H. Ide, S. Toki, Biochem. J. 119, 281 (1970)] in order tomanufacture the compound of formula Ib in accordance with embodiment (b)of the process aforesaid is conveniently carried out at a temperature of350°-700° C., especially at 400°-500° C.

The pyrolysis is conveniently carried out in an inert gas atmosphere(e.g. under nitrogen).

In the manufacture of compounds of formulae Ia and Ib there are usuallyobtained mixtures of cis/trans isomers. In the case of compounds offormula Ia the trans isomer predominates to an extent of ca 93% and inthe case of compounds of formula Ib the trans/cis ratio is ca 4:1. Theseparation of a cis/trans mixture into the individual isomers is notnecessary, but is possible. Thus, for example, the separation can becarried out according to known techniques such as column chromatography,preparative gas chromatography etc.

The compounds of formula I have particular organoleptic properties, onthe basis of which they are excellently suited as odorant and/orflavouring substances.

The invention is therefore also concerned with a method of imparting anodour and/or a flavour to materials, which method comprises applying tosaid materials or incorporating therein an odour- and/or aflavour-imparting amount of a compound of formula I in practically pureform or in the form of mixtures (with the exception of natural mixturescontaining a compound of formula I) or of an odorant and/or flavouringcomposition containing same.

The expression "practically pure" is used herein to mean, in particular,a compound of formula I which is free from accompanying substances whichare present besides compounds of formula I in natural extracts. Aspractically pure compounds of formula I in the scope of the presentinvention there should be understood, in particular, syntheticallymanufactured compounds of formula I.

The compounds of formula I, and especially those of formula Ia, havefine, tea-like, spicy, slightly woody olfactory nuances reminiscent ofdried fruits. They can therefore be used, for example, for the perfumingor aromatising of products such as cosmetics (soaps, salves, powdersetc.), detergents or foodstuffs, luxury consumables and drinks, thecompounds preferably not being used alone but rather in the form ofcompositions which contain other odorant or flavouring substances. Suchodorant or flavouring substance compositions containing a compound offormula I and their production in a manner known per se (the addition ofa compound of formula I to known odorant or flavouring substancecompositions or the admixture of a compound of formula I with natural orsynthetic compounds or mixtures suitable as components of odorant orflavouring substance compositions) likewise form part of the presentinvention.

On the basis of their very natural notes, the compounds of formula I,and especially those of formula Ia, are suitable as odorants, especiallyin combination with a series of natural and synthetic odorant substancessuch as, for example, galbanum, mastix, vetiver oil, patchouli oil,bergamotte oil, petitgrain oil, basil oil, tree moss absolute, jasmineabsolute, aldehydes, acetals, alcohols, esters, sulphur-containingcompounds (e.g. p-menthane-8-thiol-3-one etc), nitrogen-containingcompounds (e.g. indole etc), 5-methyl-heptan-3-onoxime and muskcompounds.

The odorant compositions containing the compounds of formula I areespecially attractive by their impressive freshness. In this connection,the compounds of formula I hereinbefore differ in a fundamental mannerfrom the known megastigmatrienones of similar structure [Acta. Chem.Scand. 26, 2573 (1972), U.S. Pat. Nos. 3,268,589, and 3,217,718]. Theseknown trienones of the formulae ##STR3## yield compositions havingharsh, sweet olfactory impressions.

The concentration of the compounds of formula I can vary within widelimits depending on the purpose of use; for example, between about 0.01wt. % in the case of detergents and about 15 wt. % in the case ofalcoholic solutions. In perfume bases or concentrates, the concentrationcan, of course, also be higher. The perfume bases can be used in thecustomary manner for the perfuming of Eau de Cologne, eau de toilette,lotions, creams, shampoos, soaps, detergents etc.

As flavouring substances, the compounds of formula I can be used, forexample, for the production or improvement, intensification, enhancementor modification of fruit or berry aromas in foodstuffs (yoghurt, sweetgoods etc), in luxury consumables (tea etc) and drinks (lemonades etc).

The pronounced flavour qualities of especially practically pure, andparticularly of synthetically manufactured, compounds of formula Ienable them to be used in low concentrations. A suitable range is, forexample, 0.1 ppm-100 ppm, preferably 1 ppm-20 ppm, in the finishedproduct (i.e. the aromatised foodstuff, luxury consumable or drink).

The following Table illustrates some effects which can be achieved withthe compounds of formula I.

                  TABLE                                                           ______________________________________                                        Aroma   Amount             Effect                                             ______________________________________                                        Raspberry                                                                             ppm in the finished product                                                                      greater naturality,                                        0.1-30 ppm         fruit character, full                                      especially 0.5-4 ppm                                                                             aroma                                              Tea     ppm in the finished product                                                                      very natural tea                                           0.1-100 ppm        character                                                  especially 1-20 ppm                                                   ______________________________________                                    

The compounds of formula I can be mixed with the ingredients used forflavouring substance compositions or added to such flavourants in theusual manner. Among the flavourants contemplated in accordance with thepresent invention there are to be understood flavouring compositionswhich can be diluted or dispersed in edible materials in a manner knownper se. They can be converted according to methods known per se into theusual forms of use such as solutions, pastes or powders. The productscan be spray-dried, vacuum-dried or lyophilised.

For the production of such usual forms of use there come intoconsideration, for example, the following carrier materials, thickeningagents, flavour-improvers, spices, auxiliary ingredients etc:

Gum arabic, tragacanth, salts or brewers' yeast, alginates, carrageensor similar absorbents; indoles, maltol, spice oleoresins, smoke aromas;cloves, sodium citrate; monosodium glutamate, disodiuminosine-5'-monophosphate (IMP), disodium guanosine-5-phosphate (GMP); orspecial flavour substances, water, ethanol, propyleneglycol, glycerine.

The following Examples illustrate the process provided by the presentinvention:

EXAMPLE 1

A solution of 70 g of crude 3-oxo-β-ionol and 1.5 g ofparatoluenesulphonic acid in 300 ml of toluene is stirred at refluxtemperature for 40 minutes with simultaneous removal of the water formedby means of a water separator. The cooled mixture is treated with 300 mlof ether, the organic phase is washed three times with soda solution andthree times with water, dried and concentrated. There are obtained 61 gof crude product which contains more than 90% of2,4,4-trimethyl-3-(buta-1,3-dienyl) cyclohex-2-en-1-one according togas-chromatographical analysis. Distillation of the crude product over a15 cm column gives 45 g of olfactorily-good2,4,4-trimethyl-3-(buta-1,3-dienyl) cyclohex-2-en-1-one of boiling point74°-75° C./0.06 mm Hg.

IR: 1665, 1595, 1350, 1299, 1199, 1090, 1005, 902 cm⁻¹ ;

NMR: 1.20 (6H, 2s); 1.86 (3H, s); 1.84 (2H, m); 2.48 (2H, m); 5.1-5.5(2H, m); 6.1-6.8 (3H, m) (δ in ppm);

MS: 190 (72), 175 (42), 134 (73), 133 (67), 119 (81), 105 (58), 91(100), 77 (44), 55 (47), 41 (85), 39 (56);

UV: λ max₁ 223 nm (ε₁ =12800, ethanol); λ max₂ 294 nm (ε₂ =12770).

The 3-oxo-β-ionol used as the starting material can be prepared asfollows:

To a suspension, cooled to 10° C. and well-stirred, of 192 g (1 mol) ofα-ionone and 198 g of anhydrous sodium acetate in 1 liter of methylenechloride are added dropwise over a period of 1 hour 200 g (ca 1.05 mol)of 40% peracetic acid in such a manner that the temperature does notexceed 20° C. The external cooling source is then removed and themixture is stirred at room temperature for 5 hours. In the course of thefirst hour the temperature of the mixture rises to 28° C. and thereafteragain falls slowly. The mixture is freed from sodium acetate byfiltration and the clear solution is washed twice with water, four timeswith soda solution and once again with water until it is neutral. Afterdrying over sodium sulphate and concentration, there are obtained 215 gof crude product which contains more than 94% of α-ionone epoxideaccording to gas-chromatographical analysis.

To a solution of 215 g (ca 1 mol) of crude α-ionone epoxide in 700 ml ofmethanol is added dropwise over a period of 5 minutes a freshly preparedsodium methylate solution (obtained by dissolving 2.9 g of sodium in 100ml of methanol). The mixture is then stirred at the reflux temperatureof the methanol for 3 hours, half of the methanol is distilled off undera water-jet vacuum, the concentrate is treated with a four-fold amountof water and the product is extracted with ether. After drying andconcentration of the ether phase, there are obtained 213 g of crudeproduct which contains more than 85% of4-(2,6,6-trimethyl-3-hydroxy-cyclohex-1-en-1-yl)-but-3-en-2-oneaccording to gas-chromatographical analysis. Distillation of the crudeproduct over a 15 cm Widmer column gives 155 g (75% yield based onα-ionone used) of product having a purity above 94% and a boiling pointof 131°-132° C./0.05 mm Hg.

IR: 3420, 1670, 1609, 1254, 1175, 1077, 1025, 998, 979, 962 cm⁻¹ ;

NMR: 1.08 and 1.09 (each 3H, s); 1.86 (3H, s); 2.33 (3H, s); 4.04 (1H,m); 6.10 (1H, d, J˜16 cps); 7.24 (1H, d, J˜16 cps) δ ppm;

MS: m/e 208 (33), 137 (15), 123 (22), 109 (67), 93 (12), 91 (15), 55(12), 43 (100), 41 (26), 39 (15).

To a solution, pre-cooled to 0° C., of 140 g (0.068 mol) of4-(2,6,6-trimethyl-3-hydroxy-cyclohex-1-en-1-yl)-but-3-en-2-one in 500ml of ether are added dropwise over a period of 10 minutes 700 ml of anaqueous solution, cooled to 0° C., of 202.6 g of sodium dichromatedihydrate and 186 g of concentrated sulphuric acid with intensivecooling and good stirring so that a temperature of 5° C. is notexceeded. The mixture is then stirred for a further 5 minutes at 5° C.,treated with 500 ml of ether, the ether phase is washed three times withwater, three times with soda solution and again three times with water,dried over sodium sulphate and concentrated. Distillation of theresulting 125 g of crude product over a 10 cm Widmer column gave 103 gof more than 94% pure 4-(2,6,6-trimethyl-3-oxo-cyclohex-1-en-1-yl)-but-3-en-2-one of boiling point 109°-110° C./0.05 mm Hg; melting point50°-51° C.

IR: 1665, 1615, 1248, 1173, 978 cm⁻¹ (in chloroform);

NMR: 1.19 (6H, 2s); 1.79 (3H, s); 1.85 (2H, t, J˜7 cps); 2.33 (3H, s);2.52 (2H, t, J˜7 cps); 6.12 (1H, d, J˜16 cps); 7.21 (1H, d, J˜16 cps) δppm;

MS: m/e 206 (7), 163 (21), 135 (10), 121 (19), 91 (15), 77 (12), 65(12), 55 (16), 43 (100), 41 (28), 39 (20).

To a solution, cooled to 10° C., of 72 g (0.35 mol) of4-(2,6,6-trimethyl-3-oxo-cyclohex-1-en-1-yl)-but-3-en-2-one in 400 ml ofmethanol are added portionwise over a period of 10 minutes withsimultaneous stirring and external cooling a total of 4.0 g (0.106 mol)of sodium borohydride in such a manner that the temperature does notexceed 13° C. The mixture is then stirred for a further 15 minutes at10° C., treated with a four-fold amount of water and the product isextracted with ether. After drying and concentration of the ethersolution, there are obtained 73 g of crude product which contains morethan 90% of 4-(2,6,6-trimethyl-3-oxo-cyclohex-1-en-1-yl)-but-3-en-2-ol(3-oxo-β-ionol). 3 g of the crude product are purified by columnchromatography. The product, which is more than 97% pure, is used forthe characterisation.

IR: 3420, 1660, 1595, 1200, 1139, 1095, 1030, 970, 940 cm⁻¹ ;

NMR: 1.18 (6H, 2s); 1.37 (3H, d, J˜7 cps); 1.89 (2H, t, J˜7 cps); 2.52(2H, t, J˜7 cps); 4.50 (1H, m), 5.70 (1H, d from d, J_(AB) ˜16 cps,J_(AX) ˜5.5 cps); 6.27 (1H, d, J˜16 cps);

MS: m/e 208 (8), 193 (22), 165 (100), 137 (26), 109 (22), 107 (24), 91(22), 77 (20), 55 (21), 43 (69), 41 (43).

EXAMPLE 2

The pyrolysis apparatus consists of a quartz tube having a length of 50cm and a diameter of 5 cm, which is filled with glass rings of 2-4 mmdiameter and is conditioned to a temperature of 500° C. with a heatingmantle.

8.0 g (0.034 mol) of 3-oxodihydro-β-ionyl acetate are dissolved in 30 mlof benzene and dropped into the pyrolysis tube over a period of 20minutes while simultaneously passing through a nitrogen stream of 0.3liter/minute. The pyrolysis product is condensed in a cooled vessel,diluted with 30 ml of hexane, washed twice with a sodium bicarbonatesolution and twice with water, dried and concentrated. Distillation ofthe resulting crude product (5.0 g) over a 5 cm Widmer column gives 3.5g of product of boiling point 69°-70° C./0.05 mm Hg, which is composedof 80% of 2,4,4-trimethyl-3-(but-trans-2-en-1-yl)-cyclohex-2-en-1-oneand of 20% of the corresponding cis isomer. A sample purified bypreparative gas chromatography is used for the characterisation:

IR: 1670, 1610, 1199, 1082, 1030, 965 cm⁻¹ ;

NMR: 1.13 (6H, 2s); 1.75 (3H, s); 1.69-1.75 (3H); 1.82 (2H, m); 2.48(2H, m); 2.98 (2H); 5.4 (2H, m) δ ppm;

MS: 192 (57), 138 (39), 137 (100), 121 (37), 109 (47), 93 (27), 81 (29),77 (26), 67 (25), 55 (40), 41 (72).

The compound has a balsamic, camphorous, fruity, woody odour and isreminiscent in certain respects of myrrh and opopanax.

EXAMPLE 3

A solution of 3.80 g (0.02 mol) of2,4,4-trimethyl-3-(buta-1,3-dienyl)-cyclohex-2-en-1-one, prepared asdescribed in Example 1, in 20 ml of ethanol is treated with 0.1 g ofcatalyst (palladium, 10% on active carbon) and the mixture ishydrogenated at normal pressure until 0.04 mol of hydrogen has beentaken up. After filtration, concentration and bulb-tube distillation,there are obtained 3.2 g of product which contains more than 85% of2,4,4-trimethyl-3-butyl-cyclohex-2-en-1-one according togas-chromatographical analysis.

IR: 1670, 1610, 1199, 1080, 1032 cm⁻¹ ;

NMR: 0.93 (3H, t, J˜6 cps); 1.14 (6H, 2s), 1.76 (3H, s); 1.80 (2H, m);2.48 (2H, m) δ ppm;

MS: 194 (21), 138 (40), 137 (100), 123 (17), 109 (50), 95 (25), 81 (23),67 (21), 55 (43), 41 (60).

The compound has a cedarous-woody, green, slightly spicy, fruity odour.

EXAMPLE 4

2,4,4-Trimethyl-3-(but-trans-2-en-1-yl)-cyclohex-2-en-1-one, prepared asdescribed in Example 2, can also be catalytically hydrogenated in amanner analogous to that described in Example 3 to give2,4,4-trimethyl-3-butyl-cyclohex-2-en-1-one. The yield is 82%.

The following Examples A to M demonstrate how a wide palette of odorantbases can be enriched or improved in a desirable manner by addition ofcompounds of formula I, or also how bases of quite novel odourdirections can be produced. In the compositions of Examples A-K, theeffect realised by compounds of formula I could not be obtained byaddition of the same amounts of megastigmatrienones (in the form oftheir mixtures). All such compositions lacked, in particular, thecharacteristic freshness which is conveyed to them by the addition ofcompounds of formula I. Particularly noticeable, moreover, is the factthat compounds of formula I in combination with certain known perfumeryraw materials (see Examples D, H) lead to a tobacco note not previouslyobservable, which surprisingly can not be realised by addition of themegastigmatrienones which are known as tobacco components.

EXAMPLE A

    ______________________________________                                        Green base             Parts by weight                                        ______________________________________                                        α-Hexylcinnamaldehyde                                                                          200                                                    Phenylethyl formate    200                                                    n-Hexylsalicylate      200                                                    Galbanum synthetic     60                                                     Propylphenylethyl acetal                                                                             60                                                     Isocyclocitral         50                                                     Cyclal (Trade Mark) (2,4-                                                     dimethyl-cyclohexen-1-                                                        carboxaldehyde         20                                                     Acetanisole            20                                                     p-Menthane-8-thiol-3-one                                                                             10                                                     Mastix oil absolute    10                                                     Stemone (Trade Mark) (3-methyl-                                               5-heptanoxime)         10                                                                            840                                                    ______________________________________                                    

By addition to this green base of 160 parts by weight of the compound offormula Ia, the somewhat hard green of the base is rounded very well. Ifthe galbanum odour-fixation mainly acts in the green base, then with theaddition of the compound of formula Ia the soft green of the mastixabsolute is desirably underlined. The base now acts much more flowery.

EXAMPLE B

    ______________________________________                                        Petitgrain composition                                                                             Parts by weight                                          ______________________________________                                        Phenylethyl alcohol  240                                                      Linalyl acetate      200                                                      Linalool extra       160                                                      Terpineol            100                                                      Nerol extra          100                                                      Methyl anthranilate   60                                                      Methyl naphthyl ketone                                                                              40                                                      Geranyl acetate       40                                                                           940                                                      ______________________________________                                    

By addition of 60 parts of the compound of formula Ia this petitgraincomposition is altered very strongly in the direction of Cologne. It ismuch fresher and now possesses a delicate rose note in the direction oftea-rose.

EXAMPLE C

    ______________________________________                                        Flowery composition (rose direction)                                                                 Parts by weight                                        ______________________________________                                        Phenylethyl-phenyl acetate                                                                           400                                                    Geraniol extra         300                                                    Nerol extra            100                                                    Rhodinol pure           60                                                    Citronellyl acetate     20                                                    Cinnamyl alcohol        20                                                                           900                                                    ______________________________________                                    

After addition of 100 parts by weight of the compound of formula Ia,this flowery base acts clearly less sweet, fresher, rounder, sharper andslightly spicy.

EXAMPLE D

    ______________________________________                                        Perfumery complex (wood direction)                                                                   Parts by weight                                        ______________________________________                                        Sandalwood oil         340                                                    Patchouli oil          340                                                    Vetiver oil            200                                                    Cedryl acetate          60                                                                           940                                                    ______________________________________                                    

Addition to this woody complex of 60 parts of the compound of formula Iaunexpectedly underlines the vetiver-patchouli direction therein. Thecomplex simultaneously takes on a very valuable tobacco note for men'slines, which can not be achieved in this manner with the knownmegastigmatrienones.

EXAMPLE E

    ______________________________________                                        Perfumery complex     Parts by weight                                         ______________________________________                                        Methyl dihydrojasmonate                                                                             600                                                     Bergamotte oil        300                                                     Patchouli oil          40                                                                           940                                                     ______________________________________                                    

By addition of 60 parts of the compound of formula Ia the bergamottenote in this complex is strongly displayed and the fresh effectespecially emphasised.

EXAMPLE F

    ______________________________________                                        Flowery perfumery composition                                                                        Parts by weight                                        ______________________________________                                        Phenylethyl-phenyl acetate                                                                           250                                                    Phenylethyl alcohol    200                                                    Nopyl acetate          200                                                    Phenylacetaldehyde-glyceryl acetal                                                                   100                                                    Methyl dihydrojasmonate                                                                              100                                                    Hydroxycitronellal     60                                                     Cyclamen aldehyde      40                                                     Syringa aldehyde       10                                                     Benzyl acetate         10                                                     Linalool extra         10                                                     Indole (10% in ethyl phthalate)                                                                      6                                                      C.sub.11 -aldehyde (10% in ethyl                                              phthalate)             4                                                                             990                                                    ______________________________________                                    

When there are added to this flowery composition 10 parts of thecompound of formula Ia, the composition is desirably rounded, and it nowacts softer and desirably in the direction of muguet.

EXAMPLE G

    ______________________________________                                        Perfumery composition (tea direction)                                                                Parts by weight                                        ______________________________________                                        Bergamotte oil         200                                                    a-Hexylcinnamaldehyde  160                                                    Geraniol extra         120                                                    Linalool extra         120                                                    Allylphenoxy acetate   120                                                    Methylisoeugenol       120                                                    Petitgrain oil Paraguay                                                                               60                                                    Basil oil               60                                                                           960                                                    ______________________________________                                    

When there are added to this basic composition (Cologne direction) 40parts of the compound of formula Ia, the composition is brought verywell in the direction of tea. There sets in a very fresh, sharp effectwhich underlines the shell note.

EXAMPLE H

    ______________________________________                                        Chypre composition     Parts by weight                                        ______________________________________                                        Bergamotte oil         300                                                    Citronellol extra      200                                                    Patchouli oil          100                                                    Vetiver oil            100                                                    Hydroxycitronellal     100                                                    Eugenol extra           80                                                    Tree moss absolute (50% in ethyl                                              phthalate)              20                                                    Styrallyl acetate       20                                                    Methylnonyl acetaldehyde (10% in                                              ethyl phthalate)        20                                                                           940                                                    ______________________________________                                    

When there are added to this Chypre composition 60 parts of the compoundof formula Ia, the composition is considerably less woody, it isfresher, sharper and there is obtained a very fine tobacco note.

EXAMPLE I

    ______________________________________                                        Cologne base           Parts by weight                                        ______________________________________                                        Bergamotte oil         200                                                    Geraniol extra         200                                                    Hydroxycitronellal     200                                                    Methyl 1-methylcyclododecyl ether                                                                    200                                                    N-Hexyl salicylate     100                                                    Galbanum oil            10                                                    Cyclamen aldehyde       10                                                                           920                                                    ______________________________________                                    

When there are added to this Cologne base 80 parts of the compound offormula Ib, the resulting base acts much fresher, sharper and leavesbehind upon use the impression of cleanliness. In the novel base thecitrus peel character is brought into prominence in a desirable manner.

EXAMPLE J

    ______________________________________                                        Lily of the valley base                                                                             Parts by weight                                         ______________________________________                                        Alcohol 96°    110                                                     Phenylethyl alcohol   300                                                     Hydroxycitronellal    300                                                     Benzyl acetate        150                                                     Methyl dihydrojasmonate                                                                             30                                                      Linalool extra        20                                                      Citronellol           20                                                      Citronellyl acetate   10                                                      Cyclamen aldehyde     10                                                                            950                                                     ______________________________________                                    

When there are added to this conventional lily of the valley base 50parts of the compound of formula Ib, the novel base acts much rounder,softer and more flowery. The somewhat hard note of the benzyl acetate issuppressed. The novel base surprisingly takes on an impressive ylangnote.

EXAMPLE K

    ______________________________________                                        Perfume composition with rose character                                                               Parts by weight                                       ______________________________________                                        Phenylethyl alcohol     300                                                   Geraniol extra          250                                                   Jasmin "lavage"         200                                                   Citronellol extra       100                                                   Musk ketone              50                                                   α-Ionone           30                                                   C.sub.10 -aldehyde (10% in propylene-                                         glycol)                  5                                                    C.sub.11 -aldehyde (10% in propylene-                                         glycol)                  5                                                                            940                                                   ______________________________________                                    

When there are added to this conventional rose composition 60 parts ofthe compound of formula Ic, the odour characteristic is altered towardsthe valuable direction of tea rose. If the citronellol dominates in theoriginal base, then in the novel base the geraniol is in the foreground.The novel base acts much more flowery. It is more radiation power anddiffusion.

EXAMPLE L

    ______________________________________                                                          Parts by weight                                             Raspberry aroma     A          B                                              ______________________________________                                        Acetic acid         1.0        1.0                                            Acetic acid isoamyl ester (10% in                                             propyleneglycol)    1.5        1.5                                            Dimethylsulphide (10% in                                                      propyleneglycol)    2.0        2.0                                            Vanillin            2.0        2.0                                            Acetic acid benzyl ester                                                                          3.0        3.0                                            Lemarome (Trade Mark) (citral)                                                (1% in propyleneglycol)                                                                           4.0        4.0                                            Raspberry aroma     20.0       20.0                                           Propyleneglycol     966.5      957.5                                          Compound of formula Ia (1% in                                                 propyleneglycol)    --         9.0                                                                1000.0     1000.0                                         Dosage 100 g/100 liters                                                       ______________________________________                                    

By addition of the compound of formula Ia there is attained in aroma Bthe impression of a much greater naturality in that the substantiallywoody note which is now developed advantageously underlines the fruitcharacter and thus confers to the conventional raspberry aroma A morefullness and fruitiness.

EXAMPLE M

    ______________________________________                                                             Parts by weight                                          Tea aroma              A        B                                             ______________________________________                                        Linalool synthetic (1% in                                                     propyleneglycol)       1.0      1.0                                           Camphor (1% in propyleneglycol)                                                                      1.5      1.5                                           Acetic acid linalyl ester (1%                                                 in propyleneglycol)    2.0      2.0                                           Vanillin               2.0      2.0                                           Lemarome (citral) (1% in                                                      propyleneglycol)       3.0      3.0                                           Tannin (tannic acid) (5% in H.sub.2 O)                                                               100.0    100.0                                         Propyleneglycol        890.5    887.5                                         Compound of formula Ia (1% in                                                 propyleneglycol)       --       3.0                                                                  1000.0   1000.0                                        Dosage 400 g/100 liters (10% sugar syrup)                                     ______________________________________                                    

When the conventional, but less typical, aroma A is treated with thecompound of formula Ia, there is obtained a tea aroma B which, upontasting in a 10% sugar syrup solution, immediately establishes theimpression of genuine black tea.

What is claimed is:
 1. A method for enhancing the flavor of a productselected from the group consisting of fruit, foodstuffs, tea or softdrinks which comprises incorporating therewith practically pure2,4,4-trimethyl-3-(buta-1,3-dienyl)-cyclohex-2-en-1-one in an amountequal to about 0.1 parts per million to 100 parts per million of thefinal product.
 2. A method in accordance with claim 1 wherein theproduct has a raspberry flavor.
 3. A method in accordance with claim 1wherein the product has a tea flavor.